by Jayne O'Donnell, USA TODAY

by Jayne O'Donnell, USA TODAY

Federal regulators proposed on Wednesday a long-awaited test for child safety seat side-impact crash protection that consumer advocates say will bring child safety in cars more in line with protection required for adults.

The proposed National Highway Traffic Safety Administration side-impact crash test - which would use a dummy simulating a 12-month-old and new dummy simulating a 3-year-old - would require car seats to prevent harmful head contact with an intruding vehicle door and reduce crash forces transmitted to the head and chest, NHTSA says. It would cover seats for children up to 40 pounds.

NHTSA estimates that the proposal would save five lives and prevent 64 injuries annually.

The proposal has been under consideration for a decade, and child-seat makers have been moving to add side protection in the meantime. Dorel's Safety 1st, for example, sells two models - the Advance 70 Air + Convertible Car Seat and the Elite 80 3 in 1 Car Seat - which provide full-body side impact protection.

Acting NHTSA Administrator David Friedman told reporters that many existing child seats would already meet the new rule, but some will need more padding. Those would likely cost seat-makers about 50 cents a seat, he said.

Asked about the 10 years to develop the rule, Friedman said the time was needed to replicate what exactly happens in such a crash. "It's more complicated than you would think, he said.

Child safety advocate Joseph Colella agrees. He said it was clear kids were being hurt in side crashes in 2003, but no one knew exactly how. The test couldn't be developed until that was figured out, he said.

Under the proposal, car seats would be tested in a specially designed sled test that simulates a "T-bone" crash: The front of a vehicle traveling 30 mph strikes the side of a small passenger vehicle traveling at 15 mph.

There will be a three-month comment period for the proposal, and the regulations would be final after the agency reviews the comments and addresses any issues raised.The agency proposed that three years after the proposal is final for seat-makers to comply.

At that point, "we will have the most realistic testing and the safest car seats in the world," said Colella.